Circuit breaker with signal means



N 1954 M. BROVERMAN CIRCUIT BREAKER WITH SIGNAL MEANS Filed Dec. 29,1953 2 Sheets-Sheet l I I I Nov. 23, 1954 M. BROVERMAN 2,695,401

CIRCUIT BREAKER WITH SIGNAL MEANS Filed D80. 29, 1953 2 Sheets-Sheet 2United States Patent- CIRGUIT BREAKER -WITH SIGNAL MEANS MichaelBroverman', PittsfieltL'Mass assignor to General Electric Company,acorporation of. New York Application'Decemb'er 29, 1953', Serial No.400,898

13 Claims; (Cl; 340 -222) 2,487,534 aiwarning light circuit is.provided. When anoverload occurs .in. the electrical system to-be.protected by. the-circuit breaker, the circuit breaker w1ll' operateto close a pair of contacts. in the warning light circuit beforethecircuit breakerhas tripped open. Accordingly, .be-

fore the overload trip level of the circuit breaker has been reached, awarning is given-of the presence of an overloadin said electricalsystem.

When such a type of circuit breaker is used to protect a transformerapparatus, the circuit breaker is positioned inthe transformer tankbelowthe oil level. An operating shaft extends through atside wall ofthe tank and the circuit breaker can. be operated manually fromexterially of the transformer tank .by manipulating an operatinghandle-connected to the exterior end of said shaft.

If the warning light is on and the circuit breaker has trippedopem-thecircuitbreaker can be reset and closed and the light canbe put off byfirst turning the operating handle counterclockwise and. then clockwise.If the warninglight isv on but the circuit breaker has not tripped open,the light can be put. off :merelyby turning the operating handleclockwise. However, the circuit breaker is soconstructed that even whenthe breaker has tripped open the warning light can still beput off byturning the operating handle clockwise without resetting and closing thecircuit breaker. The consequence of this lastmentioned COllditlOI'lxiSthat with the light on and the circuit breaker tripped open van operatormay put off the warning light but neglect to reset and close the circuitbreaker.

It is .anobject of this invention to provide means in the typeofcircuit'breaker just described whereby the warning. light cannot be putoff. when the circuit breaker has tripped open without first resettingthe circuit breaker.

In a circuit breaker provided withv a warning light circuit,said circuitbreaker operable to close a pair of contactsin. said circuit beforesaidcircuit breaker has tripped open, a shaft for manually controllingsaid circuit breaker,

said shaft rotatable..betweentwo extremes first. inone direction andthenin an opposite direction toreset and close said circuit breaker and opensaid pair of contacts when said circuit breaker is tripped open, androtatable in said opposit'edirectionto-open said pair .of contacts whensaid circuit breaker is tripped vopen or closed, my invention comprisesmeans for prohibiting'rotationiof said shaft in said opposite direction.to open saidpair of contacts when.

said circuit breaker is tripped' open whereby when said circuit. breakeris tripped open saidpair of contacts can be opened only by firstresetting said circuit breaker.

In. a circuit breaker.providedwitha warning light circuit,saidlcircuitzbreakeroperable.to close a pair .of con-- tactsinsaidzcircuit before said circuit breaker has tripped open, movable.means for controlling said .circuit breaker,

said means movable inone direction to open. or reset said circuitbreaker, said meansmovablein an opposite direction to-closesaidicircuit. breaker, saidmeans movable in. either: of said d rections.toopen sald, contacts when said.

circuit breaker i3 ciosed or tripped open, .rrny' invention farthercomprises nieansfor prohibitingn ovement of said 1 movable -means insaid opposite direction to open said contacts'iwhenisaid" circuitbreaker is..trippfi=d open where- 2,695,401 Patented Nov. 23, 1954 Theinvention wiil be better understood by considering:

the followingdescription taken in connection with the accompanyingdrawings, and its scope will be pointed out in the appended claims.

In the drawings,'Fig.l is partly broken away, perspectiveview of .anembodiment of my invention when in the warning light on, circuit breakertrippedopen position. Fig.2 is a sectional view taken along the line 22of Fig. 1. Fig. 3 is another view'of the apparatus shown in Fig. 1 whenin the warning light otf, circuit breaker reset and open position. Fig,4 isstill another view of the apparatus shown in Figs; 1 and 3 when inthe warning light off, circuit. breaker'reset and closed position.Throughout the various figures like :reference numerals will. be used toindicate identical parts.

Referringnow to the drawings, and more particularly to Fig. l,illustrated therein is a circuit breaker 10 adapted to protect atransformer 11 or other electrical apparatus contact 12 is carried bythe forward end of a switch arm.

14. Switch arm 14 is pivotally mounted adjacent its rear end on a shaft15. Stationary contact 13 is con-v nected to and in electrical contactwith the forward end of a bimetallic element 16. The forward end of.bi-.

metallic element 16 is rigidly fixed and the rear end ofbimetallicelement .16 is free whereby said rear end is adapted tobedeflected upwardly upon an overcurrent through bimetallic element 16.Movable contact 12,.

stationary contact 13, and bimetallic element 16 are electricallypositioned in'a secondary winding lead 17 of transformer 11. In Fig. lcircuit breaker 10'is shown in its tripped open position wherein contact12 and 13 .are disengaged. As will. be more clear hereinafter, when anovercurrent or thelike occurs in the secondary winding lead 17 oftransformer 11 the rear end of bimetallic element 16 will be deflectedupwardly and contacts 12 and 13 willbe snapped from: their circuitclosed position to their circuit open position. Also, as will be obviousto those skilled .in .the art, elements 12, 13, 14 and 16 areduplicated, not shown, on the right hand side of circuit breaker 10 forresponse to an overcurrent or the like in another secondary winding-lead18 of the transformer 11.

Still referring toFig; l, circuit breaker 10 is provided with a signalvcircuit comprising, light 20, a stationary'contact 21, contact 22. areillustrated in their engaged position whereby the warninglight 20 is on.As will be clearer hereinafter, circuit breaker "10 is constructed sothat contacts 21 and 22 are tripped'to'theircircuit closed positionprior to tripping open of the circuit breaker contacts 12 and 13 wherebya visual indication is given of 'an overload condition inthe transformer11 .prior to tripping: open of the circuit breaker contacts 12 and 13.

and a movable rod-like Referring now also toFig. 3 of the drawings,circuit.

contact..22 is carried .b'yan elongated bar .30 disposed substantiallyperpendicular to Iod-likejmovable contact 22 and the .latchingrbar .23;Movableacontact. 22 and'elom gated .I.bar. 30. are connected. togetherby welding or the like'andelongatedibar 30 is' biased downwardlyand'rear-' wardl'y'byan iricliriedspring 315 Rearward'movement of .1

for example, a warning In Fig. l'warning'light contacts 21 and 22elongated bar 30 is limited by an adjustable stop 32. Vertical upwardand downward movement is imparted to rod-like movable warning lightcontact 22 by virtue of a vertically extending guide slot 33 formed inone leg I portion of an inverted U-shaped support member 34, only aportion of which is shown. Much of inverted U- shaped support member 34has been broken away in Fig. 1 for purposes of clarity. However, as willbe obvious to those skilled in the art, the other not shown leg portionof support 34 is provided with a vertically extending slot similar toslot 33 for guiding the left-hand end of rod-like movable warning lightcontact 22. Also, a slot, not shown, is formed in the cross piece orbase portion of inverted U-shaped support 34 to aid in steadying andguiding elongated bar 30.

In Fig. 3, wherein the circuit breaker is shown in its reset butcontacts open position, the elongated bar 30 is illustrated as havingbeen raised upwardly whereby its lower end rests upon the upper surfaceof latching plate 26. In this raised position of bar 30, spring 31 holdsbar 30 against the adjustable stop 32. In such raised position of bar 30movable contact 22 is disengaged from the stationary contact 21 wherebythe light 20 is off.

As seen in Fig. l, the free or rear end of the bimetallic element 16carries a finger 35. Finger 35 is adapted to engage an integralprojection 36 on the latching bar 23. As hereinbefore stated, when anovercurrent occurs in the secondary winding lead 17, the free or rearend of bimetallic element 16 is deflected upwardly. Upward deflection ofthe rear end of bimetallic element 16 causes finger 35 to engageintegral projection 36 whereby the latching bar 23 is rotatedcounterclockwise against the clockwise biasing action of spring 25,shown only in Fig. 3. When latching bar 23 is rotated counterclockwisethe latching plate 26 is moved out of the downward path of movement ofthe elongated bar 30. Thereafter the lower end of elongated bar 30 isfree and clear of the latching plate 26 whereby spring 31 can causedownward movement of elongated bar 30 from the position illustrated inFig. 4 to the position illustrated in Fig. l. When'elongated bar 30moves downwardly the warning light contacts 21 and 22 are engaged to putthe light 20 on inasmuch as movable contact 22 gnovgs) downwardlysimultaneously with the elongated As seen from Figs. 1 and 3, positionedforwardly of the elongated bar 30 is an inverted generally U-shapedmember 40 having obtuse angle-shaped legs, only one of which is shown.The apexes of said angle-shaped legs point rearwardly and the lower endsof said legs are pointed in an acute V-shaped manner. Said pointed legends are positioned in acute V-shaped pivot grooves 41, only one ofwhich is shown, formed in the previously mentioned but not showninsulating material base whereby the U-shaped member 40 can be pivotedabout its pointed leg ends forwardly or rearwardly within grooves 41. Ahorizontally extending arm 42 is connected at its forward end by a rivet43 or the like to one side of the inverted generally U-shaped member 40.The connection between the horizontally extending arm 42 and U- shapedmember 40 is a lost motion connection by virtue of a slightly convexcurved and generally horizontally extending slot 44 formed within theforward end of arm 42 within which the rivet 43- is free to move.

Carried by the rear end of arm 42 is an upright U-.

shaped member 45. U-shaped member 45 underlies the rod-shaped movablewarning light contact 22 and the legs of U-shaped member 45 diverge awayfrom each other along opposite sides of the movable warning lightcontact 22. 1

In Fig. 1 the warning light 20 is on and the circuit breaker has trippedopen. To reset' and close the circuit breaker and put the warning light20 off, it is intended that the inverted U-shaped member 40 first bepivoted rearwardly and then forwardly. Upon initial rearward movement ofU-shaped member 40 the lost motion connection 43, 44 between members 40and 42 is taken up. Further rearward movement of member 40 causes arm 42to move rearwardly whereby the for li'ght 20 off but the circuit breakercontacts 12 and 13 .80 ward leg of U-shaped member 45 will engage therod'- like movable contact 22 and move contact 22 upwardly to open thewarning light circuit. In Fig. 3 the circuit: breaker 10 is shown ashaving been reset with the warning J still open. To close the circuitbreaker contacts 12 and 13 the U-shaped member 40 is now pivotedforwardly. When the U-shaped member 40 is pivoted forwardly the lostmotion connection 43, 44 is first taken up and then upon completion offorward movement of U-shaped member 40, the arm 42 will be movedforwardly slightly and the rear leg of U-shaped member 45 will engagemovable contact 22. The final position of U-shaped member 40 uponcompletion of its forward movement is illustrated in broken-line outlinein Fig. 4. A spring 46 biasing the arm 42 rearwardly will move the arm42 and U-shaped member 40 rearwardly slightly after the completion ofsaid forward movement of U-shaped member 40 to insure that the rod-likemovable warning light contact 22 lies midway between the diverging legsof upright U-shaped member 45. The wisdom of such an arrangement is thatif the bimetallic element 16 should be deflected upwardly slightly tofree the elongated bar 30 for downward movement to close the warninglight circuit when the condition of overload has not reached a highenough level to trip the circuit breaker contacts- 12 and 13 open, thewarning light 20 can be put off as soon as the overload condition isremoved, merely by pivoting member 40 forwardly from its full-lineposition in Fig. 4 to its broken-line position whereupon the rear legportion of U-shaped member 45 will engage contact 22 to open the warninglight circuit and put off the light 20. However, the disadvantage ofsuch an arrangement is that even when the circuit breaker 10 has trippedopen an operator is apt to put off the warning light 20 without firstresetting the circuit breaker merely by moving the U-shaped member 40forwardly. As will be more clear hereinafter, in my invention I providemeans whereby the U-shaped member 40 cannot be,

moved forwardly or clockwise to open the warning light circuit when thecircuit breaker 10 has tripped open. That is, if the circuit breaker hastripped open an operator can put off the warning light 20 only by firstpivoting the U-shaped member 40 rearwardly or counterclockwise to resetthe breaker.

Referring again to Fig. l, disposed between the legs of U-shaped member40 is an inverted generally Y- shaped reset member 50 having three legsor arms 51, 52 and 53. Generally Y-shaped reset member 50 is pivotallyconnected adjacent the lower end of leg 52 to a shaft 54 fixed in thenot shown previously mentioned insulating material base. An arm 55 ispivotally connected at an upper end thereof to the upper end of leg 52adjacent the forward edge of reset member 50. Another arm 56 is pivtally mounted at the lower end thereof to a shaft 57 fixed in switch arm14. The lower end of arm 55 and the upper end of arm 56 are eachpivotally connected to a freely movable or floating shaft 58. Leg 51 ofreset member 50 extends rearwardly and the upper end thereof is disposedbehind the cross-piece or base of U-shaped member 49. A spring 59 isconnected at opposite ends thereof to a rear portion of said cross-pieceor base of member 15 is a latching mechanism comprising three curvedlevers 60, 61, and 62; and a generally semi-circular cam 63 having alatching tooth 64 therein.

The circuit breaker 10 for transformer 11 can be controlled fromexteriallv of a transformer tank, not shown, enclosing circuit breaker10 and transformer 11, by properly manipulating an operating handle 70connected to the exterior end of an operating shaft 71. An aperture isformed in a side wall 72 of the transformer tank and through saidaperture extends an operating shaft guide bushing or hearing 73. Handle70 has a pointer 74 formed integrally thereon cooperative with asuitably marked dial plate portion 75. Adjacent a central portion of theoperating shaft guide bushing or bearing 73 is formed an externalshoulder 76 facing the exterior surface of side wall 72. The centralportion of guide bushing or hearing 73 positioned interially of the notshown transformer tank has threads formed thereon cooperative with aninternally threaded nut 77. When nut 77 is turned down on the centralthreaded portion of guide bushing or hearing 73' a' gasket or othersealing means positioned between external shoulder 76 and the exteriorsurface of side wall 1' will be compressed to seal the aperture in thetransformer tank side wall 72; The interior'end of operating shaft" s'71 is connected to the inverted U-shaped member 40. by anadjustablelinkage'78, 7-9. When the;operating handle 70 is'rotated clockwise theinverted U-shaped member 40 is simultaneously pivoted clockwise orforwardly, and

when operating handle 70 is rotated counterclockwise the invertedU-shaped member 40 is simultaneously pivoted counterclockwise orrearwardly.

As illustrated in Fig. '1, the circuit breaker 10 has tripped openwhereby the circuit breaker contacts 12 and 13areopen and the Warninglight contacts 21 and 22 are closed whereby the warning light 20 is on.To close the circuit breaker contacts 12 and 13, the latching mechanismfill-64 and the reset member 50 of the circuit breaker 10 must first bereset. This is' accomplished by rotating the handle 70 counterclockwiseuntil pointer 74 is at the A position of dial 75 whereby the U-shapedmember 40 will be caused to rotate counterclockwise or rearwardly. Asillustrated in .Fig. 3, when member 40 is rocked counterclockwise orrearwardly, the reset member 50 is simultaneously rockedcounterclockwise or rearwardly about its pivot 54 inasmuch as the leg 51and rear-portion of the cross piece or base portion of U-shaped member40 are in abutting relationship when the circuit breaker 10 has'trippedopen asillustrated in Fig. l. Counter-clockwise pivotal movementof the reset member 50 causes the leg 53 to move rearwardly anddownwardly whereby the latching tooth 64 of. the cam 63 is placed incontact with the upper surface of latching plate 26 as shown in vFig.3.. Simultaneously, the horizontally extending arm 42 ismovedrearwardly, whereby the forward leg of upright U-shaped member 45strikes the movable rod-like contact 22 to disengage the warning lightcontacts '21 and 22 and raise the elongated bar 30 whereby the spring 31can pull the elongated bar 30 against the adjustable stop 32. When theelongated bar 30 is raised upwardly and pulled rearwardly t1 e lower endthereof will be placed in contact with the upper surface of latchingplate 26 as illustrated in Fig. 3. It should be noted that a largerportion of the latching tooth 64 is in engagement with the latchingplate 26 than there is of the lower end of the elongated bar 30 inengagement with latching plate 26. Since a smaller portion of the lowerend of elongated bar 39 is in engagement with the latching plate 26 thanthere is of the latching tooth 64, when the bimetallic element 16deflects upwardly the elongated bar will be released for downwardmovement before the latching tooth 64-is disengaged from the latchingplate 26. Thereby, provision is made for closing of the warning lightcontacts 21 and 22 before the circuit breaker has tripped open.

As seen from Fig. 1, when the latching mechanism 69-64 and the resetmember 50 have been tripped to their circuit breaker tripped openposition, the pivot point 65 between the upper end of arm 55 and thereset member $50 is disposed forwardly of the pivot point or shaft 54for the reset'rnember 50 adjacent the lower end of leg-52. However, whenthe reset member 50 is rocked counterclockwise or rearwardly, the pivotpoint 65 is caused to move rearwardly and downwardly whereby after thelatchingmeclianism 6064 hasbeen latched the pivot point 65 is disposedrearwardly of the pivot point 54, as shown in Fig. 3. .Also, asillustrated in Fig. 3, when the circuit'breaker is in its reset c ntactsopen position the spring 59 is disposed rearwardly of the arm 55 and thereset member, 50 is held-in its latched position by virtue of theengagement of latching tooth 64 with latching plate 26.

After the latching mechanism 60-64 and reset member 50 of the circuitbreaker have been reset by counterclockwise 'movement of the handle 70,the circuit breaker contacts 12 and 13 can be closed by moving thepointer74 clockwise to the 13 position of dial plate 75. Referring nowto Fig. 4, it will be seen that when the U-shaped member 40 is rocked.clockwise or forwardly the spring 59 will be moved to a positionforwardly of the pivot point 65 of the upper end of 'arm 55.Accordingly, the buckled or collapsed lever arms 55 and 56 illustratedin Fig. 3 will now be snapped to an extended position illustrated inFig. 4 Wherebythe switch arm 14 is snapped clockwise and downwardly forengagement of the movable circuit breaker contact 12 with thestationary'circuit breaker contact 13. 'When the .U shaped member 40 is:rockedclockwise. 'or :forwardly to :close ithecircuit breaker.contaetsglizand 1:3,

simultaneously "the arm "42 sis-pulled :forwardly to .cause therear leg:of 'U-s'haped member -45 to come in contact with the movable contactThe extreme forward position of U-shaped member 40 upon clockwiserotation 'of op'erating handle 70. is illustrated in broken-line outlineinFig. 4. At the extreme end of this forward movement of member 40, thespring 46 will retract member 40 from the. broken-line position to thefull line position illustrated in Fig. 4. This action also retracts thehorizontally extending arm 42 rearwardly slightly so that therear leg of.U-shaped member 45 no longer contacts the movable warning light contact22. As seen in Fig. '4, the spring 59 will not cause the arms 55 and 56to buckle .in .an opposite direction from the buckled :position of arms-55 and :56 shown. in Figs. 1 and 3 inasmuch as arm .55 in the Fig. 4position of the circuit breaker will abut a stop 66 provided on fixedshaft 54.

When the transformer 11 is overloaded the bimetallic element 16willdeflect upwardly and cause the latching bar 23 and plate 26' to pivot.counterclockwise. Initial counterclockwisepivotal movement of thelatching plate 26 will release the elongatedbarSO-for downward movementwhereby the warning :light contacts 21 and '22 are engaged'toput on thewarning light 20 before the latching tooth 64 is disengaged from thelatching plate 26 to trip the circuit breaker contacts 12 and 13 open.As hereinbefore explained, the warning light 20 can be put off bypivoting operating handle 70 clockwise to move I the U-shaped member 40from the full-line position illustrated in Fig. '4 to the broken-lineposition illustrated in Fig. 4 while the circuit breaker contacts 12 and13 are still in the circuit closed position. Movement of theU-shapedmember 40 from the Fig. 4' fullline position to the 'Fig. 4broken-line position will move the horizontally extending arm 42forwardly to engage the rear leg of U-shaped member 45 with the movablecontact 22 to raise movable contact 22 from engagement with thestationary warning light contact 21 whereby the warning light 20 is putofi. After the warning light is put off, the spring 46 will retract theU-shaped member 40 from the Fig. 4 broken-line position to the Fig. 4full-line position. Also, spring 46 moves arm 42 rearwardlyslightly todisengage the rear leg of U-shaped member 45 from the then raisedmovable warning light contact 22.

When going from the reset circuit breaker contacts open positionillustrated in Fig. 3 to the circuit breaker contacts closed positionillustrated in Fig. 4, the buckled arms 55 and 56 were placed in theirextended position illustrated in Fig. 4. When arms 55 and 56 wereextended the spring 59 tended to move the arm 55 upwardly. An upwardthrust on arm 55 tends to move the reset member 50 upwardly also.However, due to the configuration of member 50 and the pivotal mountingof member 50 at pivot point 54 positioned in front of the pivot point 65this upward thrust on arm 55 is translated into a thrust against resetmember 50 tending to rotate member 50 clockwise or forwardly. However,reset member 50 is prohibited from rocking clockwise or forwardly byvirtue of engagement of latching tooth 64 and latching plate 26. Shoulda sufficient overload condition develop in the transformer 11 to tripthe latching mechanism 64 as well as the elongated bar 30, the pivotpoint will move forwardly of the spring59. Thereafter, the arms 55 and56 will have been buckled and the spring 59 will be free to snap theswitch arm 14 open to the tripped open position illustrated in Fig. 1.When the circuit breaker trips open from the Fig. 4- position to theFig. 1 position, the pivot point or shaft 58 is disposed rearwardly ofthe center-line of the V-shaped pointed ends of the legs of the U-shapedmember 40. Accordingly, the spring 59 will pull the U-shaped member 40rearwardly or counterclockwise slightly.

As 'hereinbefore stated, when the circuit breaker 10 trips open the,pivot point 65 is disposed forwardly of the pivot point :54..Accordingly, after the circuit breakor has tripped open, the'circuitbreaker cannot be closed by rocking the operating handle and U-shapedmember 40 clockwise. In Order 'to close the contacts 12 and 13, thespring 59;must bemoved forwardly of the pivot point 65. However,suchalarge degree of forward movement of U1shaped ;rnember 40 isprohibited by virtuemf'them peration between, the 'Vishaped tends of thelegs of U-shaped member 40 and the V-shaped pivot grooves 41. When thecircuit breaker has tripped open if the U-shaped member 40 is rockedforwardly, the forward edge of the V-shaped ends of the legs of U-shapedmember 40 will engage the forward edges of the V-shaped pivot notches41. Thereafter, forward movement of U-shaped member 40 is prohibited. Atsuch extreme forward movement of the U-shaped member 40, the spring 59has still not moved forwardly enough to be positioned in front of thepivot point 65 to distend the arms 55 and 56 to snap the switch arm 14downwardly whereby the movable circuit breaker contact 12 is engagedwith the stationary circuit breaker contact 13. However, even though thecircuit breaker cannot be closed by clockwise movement of handle 70 oncethe circuit breaker has tripped open, still the warning light 20 can beput off by clockwise rotation of handle 70 and U-shaped member 40. Forinstance, viewing Fig. 1, it will be seen that if U-shaped member 40 isrocked forwardly slightly the horizontally extending arm 42 will also bemoved forwardly whereby the rear leg of U-shaped member 45 will engageand raise the movable warning light contact 22 to open the warning lightcircuit. Opening of the warning light circuit by a slight clockwisemovement of the operating handle 70 is desirable for as explained inconjunction with Fig. 4, it is desirable for an operator to be able toopen the warning light contacts 21 and 22 after the overload conditionhas been removed by a slight clockwise pivotal movement of the U-shapedmember 40 when the circuit breaker has not tripped open. In myinvention, I providemeans for prohibiting opening of the warning lightcontacts 21 and 22 by clockwise movement of handle 70 when the circuitbreaker has tripped open to the Fig. 1 position, yet still permittingopening of said warning light contacts by clockwise movement ofoperating handle 70 when the circuit breaker contacts 12 and 13 are intheir closed position.

The locking means for prohibiting clockwise movement of operating shaft71 and member 40 when the circuit breaker 10 has tripped open to apprisean operator of the fact that the circuit breaker 10 has tripped opencomprises a circular disc or cam 80 which abuts the interior end ofguide bushing or bearing 73. Disc or cam 88 is connected to shaft 71 forrotary movement therewith by virtue of a pin 81 or the like. Disc or cam88 has an outer diameter greater than the outer diameter of bushing orbearing 73. a A rectangular-like tab or finger 82 flush with the outercylindrical surface of cam 80 and approximately perpendicular to thelefthand side of cam 80 extends therefrom'in overlying or superposedrelationship with the exterior cylindrical surface of the interior endof bushing or bearing 73. Positioned on the interior end of bushing orhearing 73 between the exterially threaded shoulder 83 of bushing 73 andcam 88 is a cylindrical or sleeve-like cam 84-. Between the cam 84 andshoulder 83 is a spring 85 continuously biasing cam 84 against cam 80.

In the right-hand end edge of cam 84 opposite to the cam 88 and oppositeto the tab or finger 82 is formed a generally L-shaped notch 86. Thelonger leg portion of notch 86 is positioned along said right-hand endedge of cam 84 and the base leg portion of notch 86 extends away fromsaid right-hand end edge of cam 84. The depth of the longer leg portionof notch 86 is less than the length of rectangular-like tab 82, whereasthe depth of the base leg portion of notch 86 is greater than the lengthof tab 82. The base edge 87 of L-shaped notch 86 is inclined or taperedwith respect to the longer leg portion of notch 86 at an angle ofapproximately 60 for a purpose hereinafter to be described.

In the left-hand end edge of cam 84 approximately diametrically oppositeto the notch 86 is formed another generally L or right-angle shapednotch 88. The shorter leg portion of notch 88 extends from saidleft-hand end edge of cam 84 towards the right-hand end edge of cam 84and is disposed with respect to said left-hand end edge of cam 84 at anangle of approximately 60 generally parallel to the base edge 87. Thelonger leg portion of notch 88 extends from the interior end of theshorter leg portion of notch 88 approximately perpendicular to the axisof sleeve-like cam 84. A stop pin'89 connected to the bushing or bearing73 is disposed within the notch 88' for a purpose hereinafter to bedescribed. As illustrated in Fig. 1, when the circuit breaker is in thetripped open position the tab 82 is disposed within the shorter legportion of notch 86 and the stop pin 89 is disposed within the shorterleg portion of notch 88. Inasmuch as cam 80 is pinned to shaft 71 andtab 82 is disposed within the shorter leg portion of notch 86, should anoperator attempt to rotate the operating handle 70 clockwise to put thewarning light 20 off, the sleeve-like cam 84 will be jammed against thestop pin 89 inasmuch as the base edge 98 of notch 88 is in abuttingrelationship with respect to the stop pin 89. Accordingly, when thecircuit breaker 10 is in the tripped open position, the warning light 20cannot be put off by pivoting handle 78 and member 40 clockwise. Withthe operating handle 70 locked against clockwise movement an operator isapprised of the fact that the circuit breaker 10 has tripped open andthat he must first reset the circuit breaker 10 by rotating theoperating handle 70 counterclockwise. When the operating handle 70 isrotated counterclockwise, the tab 82 engages the inclined base edge 87of notch 86 and imparts a counterclockwise motion to cam 84 andsimultaneously moves cam 84 away from cam 80 whereby the spring iscompressed. Movement of the cam 84 counterclockwise and away from cam 80causes the stop pin 89 to ride up the inclined shorter leg portion ofnotch 88 and then into the longer leg portion of notch 88 to theposition illustrated in Fig. 3. When the stop pin 89 reaches the closedend of the longer leg portion of notch 88 as illustrated in Fig. 3,further counterclockwise movement of operating handle 70 is prohibitedby stop pin 89 and the circuit breaker 10 is now in its reset position.With the stop pin 89 disposed within the longer leg portion of the notch88 the spring 85 is prohibited from moving the cam 84 into contact withthe left-hand side of cam 88. To close the circuit breaker contacts 12and 13 after the circuit breaker has been reset, the operating handle 70is now rotated clockwise. When the operating handle 70 is rotatedclockwise, the tab 82 will strike the edge 91 of notch 86 and rotate thecam 84 clockwise whereby the stop pin 89 will be removed from the longerleg portion of notch 88 into the shorter leg portion of notch 88. Afterthe handle 70 is rotated clockwise to move the member 40 from the Fig. 3position to the broken-line position illustrated in Fig. 4, the stop pin89 will abut the base edge 98 of notch 88 whereby further clockwisemovement of the operating handle 70 is prohibited. The spring 85 as yetcannot move the cam 84 against the cam 80 inasmuch as the tab 82 isstill disposed within the longer leg portion of notch 86. When themember 40 is moved to the broken-line position illustrated in Fig. 4,the spring 46 will retract member 40 to the full-line positionillustrated in Fig. 4 whereby a slight counterclockwise motion will beimparted to the operating shaft 71. Said slight counterclockwise motionof shaft 71 moves the tab 82 slightly counterclockwise away from theedge 91 of notch 86. However, the spring 85 still will not move the cam84 against the cam 80 inasmuch as the tab 82 is still disposed withinthe longer leg portion of notch 86. Should the warning light contacts 21and 22 in Fig. 4 be closed to place the warning light 20 on while thecircuit breaker contacts 12 and 13 are still closed, the warning light20 can be put off by rotating the operating handle 70 clockwise. Uponclockwise rotation of operating handle 70 the tab 82 will move from theposition illustrated in Fig. 4 against the edge 91 of notch 86. Uponsuch clockwise rotation of shaft 70, the U-shaped member 48 of Fig. 4will be moved from the full-line position to the broken-line position toopen the warning light contacts 21 and 22 after which the spring 46 willretract the member 40 rearwardly slightly causing the tab 82 to movecounterclockwise from a position of abutting relationship with the edge91 of notch 86 to the nonabutting position shown in Fig. 4. Ashereinbefore described with reference to Fig. 4, when the circuitbreaker 10 trips open the U-shaped member 40 is rocked counterclockwiseslightly from the Fig. 4 full-line position. counterclockwise rotationof member 40 from the fullline position illustrated in Fig. 4 causes thetab 82 to move counterclockwise opposite to the shorter leg portion ofnotch 86. When the tab 82 is disposed opposite to the shorter legportion of notch 86, the cam 84 is then free to be moved against cam 80by the spring 85 inasmuch as the stop pin 89 is disposed without thelonger leg portion of :notch 88 and within the shorter leg portion. ofnotch 88. Accordingly,xwhen the. circuit. breaker v10. tripsopeni thespring 85 will drive the cam 84. towards cam. 8fl whereby- 'thertab. 82will be disposed within the shorter leg portiozrof notch 86 asillustrated in the Fig. 1 position of the locking cam means Asillustrated in Fig. 1, when the spring 85 drives the cam 84 against thecam 80 to position the tab 82 within the shorter leg portion of notch86, the stop pin 89' is disposed in abutting relationship with respectto the edge 90 of notch 88 whereby the operating handle 70 cannot berotated clockwise to turn the warning light 2070i? without firstrotating, the operating handle 70 counterclockwise to reset thecircuitbreaker 10.

While there has been shown: and described a particular embodiment of theinvention, it will be obvious to those skilled in the art that changesand modifications may be made without'd'eparting from the-invention, andit is intended by the appended claims to cover. all such changes andmodifications as: fall within the true spirit and scope "of theinvention.

What I claim asv new and desire to secure by Letters Patent of theUnited States is:

1. A circuit breaker provided with. a signal: circuit, said circuitbreaker operable to close a pair of. contacts in saidsignalcircuitbefore saidcircuit breaker has tripped open, means movable inoppositedirections for controlling said circuit breaker, said meansmovable only first in one direction and then in another direction toclose said circuit breaker when in a tripped open. position, and

movable in said another. direction to open said. pair of.

contacts only when said circuit breaker isclosed.

2. A circuit breaker provided with a signalcircult, said circuit breakeroperable to close a pair of contacts in said signal circuit before saidcircuit breaker has tripped open, movable means for resetting saidcircuit breaker when in a tripped open position and for opening, saidcontacts when said contacts are closed, said means actuatable only inone directionto reset said breaker, said means actuatable in either saidone or another directionto open said contacts, and other meansprohibitingmovement of said movable means in said another direction whensaid circuit breaker is in a tripped open position.

3. In a circuit breaker having a warning light circuit, said circuitbreaker operable to close said warning light circuit prior to trippingopen of said circuit breaker, a shaft for resetting saidcircuit breakerafter said circuit breaker has tripped open and for opening. saidwarning.

light circuit before and after said circuit breaker has tripped open,said circuit breaker when in the tripped open position reset only byfirst rotating said shaft in one direction, said light circuit whenclosed opened by rotating said shaft in said one direction or anotherdirection opposite to said one direction, locking means for prohibitingrotation of said shaft in said another direction when said circuitbreaker is in a tripped open position whereby said shaft can only befirst rotated in said one direction when said circuit breaker is in atripped open position.

4. In a circuit breaker having a pair of circuit breaker contacts, areset member cooperative with a latching mechanism whereby said circuitbreaker contacts can be closed only after said reset member is movedfrom a tripped position to a reset position whereby said reset member islocked by said latching mechanism in said reset position, said' circuitbreaker having a pair of warming light contacts, said circuit breakeroperable to close said warning light contacts prior to unlocking of saidlatching mechanism when said circuit breaker contacts are closed, saidcircuit breaker having means for moving said reset member from saidtripped position to said locked reset position and for opening saidwarning light contacts only with simultaneous movement of said resetmember from said tripped position to said locked reset position orsubsequent to said movement while said reset member is in said lockedreset position.

5. In a circuit breaker having a warning light, said circuit breakeroperable to put said warning light on prior to tripping open of saidcircuit breaker, a shaft for manually operating said circuit breaker,said shaft rotatable only in one direction to reset said circuit breakerwhen said circuit breaker has tripped open, said shaft rotatable ineither said one direction or another direction opposite to said onedirection to put said light ofi when said light is on, means forprohibiting rotation of said shaft in said another direction when saidcircuit breaker has tripped open. comprising: av stationary bushing. forsaid. shaft,, a cam. connected. to. said shaft. and. rotatabletherewith,-a movable cam on saidbushing continuously urgedagai'nst saidshaftzconnectedcam, said shaft connectedcarn having a tab thereoncooperative with a notch in said movable cam, and another notch in saidmovable cam cooperative with a stop member connected to said bushing.

6. In a circuit breaker adapted to protect an electrical apparatus froman overload, said circuit breaker having signal means, said circuitbreaker adapted to actuate said signal means. from a non-indicatingcondition to an indicating; condition upon an overload in saidelectrical; apparatus prior to tripping open of said circuit breaker,movable means. for manually operating, said circuit breaker, saidcircuit breaker when in a tripped open position reset only by actuatingsaid movable means in one direction, said signal means when in an.indicating condition returnable to a non-indicating condition byactuating said movable means either in said one direction or in: anotherdirectoin opposite to said one direction, and means for prohibitingactuation of said movable meansv in said another direction when saidcircuit breaker is in a tripped open position whereby when said circuitbreaker is in a tripped open position said signal means can be returnedto said-non-indicating condition only by actuating said movable means insaid one direction whereby said circuit breaker will be simultaneouslyreset.

7. In acircuit breaker adapted to protect an electrical system from anoverload, said circuit breaker having asignal means, said circuitbreaker adapted to actuate saidv signal means from a non-indicatingcondition to an indicating condition upon the occurrence of an overloadin said electrical system prior to tripping open of said circuit breakerfroma reset closed position, a movable control member connected to saidcircuit breaker for controlling said circuit breaker and signal means,said circuit. breaker when in a tripped open position returnable to areset closed position only by first actuating said control member in onedirection and then in another direction'oppostte to said one direction,said signal means when in an indicating condition returnable to saidnon-indicating condition by actuating said control member either in saidone direction or said another direction, and locking means comprising astop member for prohibiting actuation of said control member in. saidanother direction when said circuit breaker is in a tripped openposition while still permitting actuation of said control member in saidanother direction when said circuit breaker is in a reset closedposition whereby when said circuit breaker is in a tripped open positionsaid signal means can be returned.

to said non-indicating condition only by actuating said control memberin said one direction whereby said circuit breaker will besimultaneously returned from a tripped open position-to a resetposition.

8. In a circuit breaker adapted to protect an electrical apparatus froman overload, said circuit breaker having, signal means, said circuitbreaker adapted to actuate said signal means from a non-indicatingcondition to an indicating condition upon the occurrence of an overloadin said electrical apparatus prior to tripping open of said circuitbreaker from a reset closed position, an operating shaft for operatingsaid circuit breaker and signal means, said circuit breaker when in atripped open position returnable to a reset closed position only byfirst rotating said shaft in one direction and then in another d1rect1onopposite to said one direction, said signal means when in an indicatingcondition returnable to said nonindicating condition by rotating saidshaft in either said one direction'or said another direction, andlock-ing means for prohibiting rotation of said shaft in said anotherdirection when said circuit breaker is in a tripped open positionwhereby when said circuit breaker is in a tripped open position saidsignal means can be returned to said non-indicating condition only byfirst rotating said shaft in said one direction whereby said circuitbreaker will be simultaneously reset, said locking means comprising animmovable bearing for said shaft, a circular cam fixed to said shaft androtatable therewith, a movable sleevelike cam on said bearingcontinuously urged for movement against said circular cam, said circularcam having a tab thereon cooperative with a notch in said movablesleeve-like cam, and another notch in said movable sleeve-like camcooperative with a stop member fixed to said immovable bearing.

9. In a circuit breaker adapted to protect an electrical apparatus fromoverloads, said circuit breaker havinga warning light, said circuitbreaker adapted to put sa d warning light on upon the occurrence of anoverload 111 said electrical apparatus prior to tripping open of saidcircuit breaker from a reset closed position, a shaft connected to saidcircuit breaker for manually operating said circuit breaker and warninglight, said circuit breaker when in a tripped open position returnableto a closed position only by first rotating said shaft counterclockwiseto reset a tripping mechanism in said circuit breaker after which saidcircuit breaker can be closed by then rotating said shaft clockwise,said warning light when on put off by rotating said shaft eithercounterclockwise or clockwise when said circuit breaker is either in atripped open position or in a reset closed position, locking meanscomprising a 'stop member for prohibiting clockwise rotation of saidshaft when said circuit breaker is in a tripped open position whilestill permitting clockwise rotation of said shaft when said circuitbreaker is in a reset closed position whereby said warning light can beput off when said circuit breaker is in a tripped open position only byrotating said shaft counterclockwise and simultaneously resetting saidtripping mechanism.

10. In a circuit breaker adapted to protect an electrical apparatus fromoverloads, said circuit breaker having a warning light, said circuitbreaker adapted to put said warning light on upon the occurrence of anoverload in said electrical apparatus prior to tripping open of saidcircuit breaker from a reset closed position, a shaft connected to saidcircuit breaker for manually operating said circuit breaker and warninglight, said circuit breaker when in a tripped open position returnableto a closed posit-ion only by first rotating said shaft counterclockwiseto reset a tripping mechanism in said circuit breaker after which saidcircuit breaker can be closed by then rotating said shaft clockwise,said warning light when on put off by rotating said shaft eithercounterclockwise or clockwise when said circuit breaker is either in atripped open position or in a reset closed position, locking means forprohibiting clockwise rotation of said shaft when said circuit breakeris in a tripped open position while still permitting clockwise rotationof said shaft when said circuit breaker is in a reset closed positionwhereby said warning light can be put off when said circuit breaker isin a tripped open position only by rotating said shaft counterclockwiseand simultaneously resetting said tripping mechanism, said locking meanscomprising an immovable bearing for said shaft, a circular cam fixed tosaid shaft and rotatable therewith, said bearing having a sleeve-likemovable cam thereon continuously urged towards said circular cam, a tabconnected to said circular cam and extending therefrom into a generallyL-shaped notch formed in an edge of said sleevelike cam opposite to saidcircular cam, a base edge portion of said notch inclined with respect tosaid end edge at an angle of approximately 60 degrees, another generallyL-shaped notch formed in another end edge of said sleeve-like cam, abase leg portion of said another notch inclined with respect to saidanother end edge at an angle of approximately 60 degrees, and a stop pinfixed to said bearing and disposed within said another notch.

11. In a shaft journaled within a bearing for rotation in one directionand in another direction opposite to said one direction, means forprohibiting rotation of said shaft in said another direction after saidshaft has rotated beyond a predetermined point in said one direction,said means comprising a cam fixed to said shaft and rotatable therewith,a movable cam on said bearing, said movable cam continuously urged formovement towards said shaft fixed cam, said shaft fixed cam having a tabextending? therefrom into a notch formed in said movable cam opposite tosaid tab, said movable cam having another notch formed therein, and astop member fixed to said bearing disposed within said another notch.

12. In a shaft journaled within a stationary bearing for rotation inopposite direction-s between two extremes, said shaft rotatable in onedirection from one of said extremes to another of said extremes androtatable in another direction opposite to said one direction from saidanother extreme to said one extreme, locking means for prohibitingrotation of said shaft in said another direction after said shaft hasbeen rotated in said one direction from said one extreme beyond apredetermined point disposed between said two extremes without firstrotating said shaft in said one direction to said another extreme, saidlocking means comprising a cam fixed to said shaft and rotatabletherewith, a movable cam on said bearing continuously urged for movementtowards said shaft fixed cam, a finger extending from said shaft fixedcam into a notch formed in said movable cam opposite to said finger,another notch formed in said movable cam, and a stop member fixed tosaid bearing disposed within said another notch.

13. In a shaft journaled for clockwise and counterclockwise rotation ina stationary cylindrical bearing between two extremes, locking means forprohibiting clockwise rotation of said shaft after said shaft has beenrot-ated counterclockwise from one of said extremes past a pointdisposed between said two extremes without first rotating said shaftcounterclockwise to another of said extremes, said locking meanscomprising an annular cam having an outer diameter greater than an outerdiameter of said cylindrical bearing fixed to said shaft and rotatabletherewith, a rectangular-like tab extending from said cam intosuperposed relationship with an outer cylindrical surface of saidcylindrical bearing, a movable sleeve-like c am positioned on saidcylindrical bearing, a spring continuously biasing said movable camtowards said annular cam, a first generally L-shaped notch formed in anend edge of said'movable cam opposite to said annular cam, a longer legportion of said notch extending generally normal to the axis of saidmovable cam and a shorter base leg portion of said notch extendinggenerally parallel to said axis, the length of said tab being greaterthan the depth of said longer leg portion but less than the depth ofsaid shorter base leg portion, said tab disposed within said notch andcooperative therewith, a base edge of said shorter base leg portioninclined with respect to said end edge at an angle of about 60 degrees,another generally L-shaped notch formed in said movable camapproximately diametrically opposite to said first notch in another endedge of said movable cam, a shorter base leg portion of said anothernotch extend- 1ng from said another end edge towards but short of saidannular cam and inclined with respect to said another end edge at anangle of about 60 degrees, a longer leg portion of said another notchextending from an inner end of said another notch shorter base legportion generally normal to said axis, a stop pin fixed to said bearingdisgxosed within said another notch and cooperative there- Wl ReferencesCited in the file of this patent UNITED STATES PATENTS Number Name Date2,468,645 Steinm'ayer Apr. 26, 1949 2,586,429 Hodnette et al Feb. 19,1952

